Role of Microbial Decomposers in Enhancing Enzyme Activity and Nutrient Release from Wheat Straw

This study evaluated the effects of microbial inoculants, especially crop residue decomposers, on enzymatic activities and soil health during wheat straw decomposition. Results indicate that microbial inoculation significantly improved microbial counts, microbial biomass carbon (C), nitrogen (N), basal soil respiration, soil enzymes and other soil properties, except soil pH. Among the treatments, CRDB48 demonstrated the highest microbial activity, followed by CRDB24, CRDB52, CRDF32 and CRDF8. Enzyme activities, such as β-glucosidase, protease, xylanase and chitinase, varied significantly among treatments. β-glucosidase activity ranged from 12.46 to 39.60 μg PNP g^-1 soil h^-1 with CRDB48 showing the highest activity (39.6 μg PNP g^-1 soil h^-1). Protease activity ranged from 9.17 to 30.5 μg try g^-1 soil h^-1 also highest in CRDB48 (30.5 μg try g^-1 soil h^-1). Xylanase activity peaked in CRDB24 (141.76 μg GE g^-1 soil h^-1), while chitinase activity was highest in CRDB48 (1.33 μg N-acetyl glucosamine g^-1 soil h^-1). Soil organic carbon (SOC) ranged from 0.37% to 0.51%, with the highest in CRDB48. Total carbon varied from 25.0 to 34.2 mg kg^-1 CRDB48 exhibited the highest available nitrogen (246.7 kg ha^-1), while CRDB24 and CRDF32 showed the highest available phosphorus (18.41 kg ha^-1). Molecular identification revealed Bacillus haynesii (CRDB24), Bacillus altitudinis (CRDB48) and Bacillus stratosphericus (CRDB52) as predominant species, alongside fungal isolates Fusarium oxysporum and Aspergillus fumigatus. These findings highlight the potential of microbial inoculants in enhancing soil health and promoting sustainable agriculture.